Twenty-six-years later, Rhianna Barreau remains missing

LIKE a number of Aussie kids in the early '90s, 12-year-old Rhianna Barreau had an overseas penpal.

She had built up quite a bond with her American correspondent, and wanted to buy her a Christmas card.

It was only October, but this was 1992, and international post was slower in those days. Her mother Paula had to work that day, but Rhianna was on school holidays, and so the pair arranged for Rhianna to walk to a nearby newsagency to buy the card. There was a bus strike that day, so walking was her only option.

Rhianna's mother left the house at 8:30am that morning.

It was the last time she would see her daughter alive.

Rhianna Barreau. Picture: Supplied

In the 26 years that have passed, Rhianna's whereabouts have remained unknown, despite extensive search efforts and public pleas.

Rhianna Barreau lived in Morphett Vale, South Australia.

Her home, on Wakefield Avenue, was roughly 250 metres from the Southern Expressway, which cut through the suburb, parallel to her street.

Morphett Vale is a busy suburb, but a suburb all the same, so Rhianna's mother wasn't too concerned about her walking alone to the nearby shopping centre.

Rhianna Barreau wanted to buy her American penpal a Xmas card. Picture: Supplied

Throughout that day, Rhianna's movements were clocked by a number of individuals. According to eye witness reports, she was seen leaving her home at 10:30am, presumably to walk to the newsagency.

Records show that she bought the card at 11:19am at the Reynella Shopping Centre, and was later spotted cutting through both Morphett Vale High School and Stanvac Primary School during a half-hour window shortly after noon.

In both instances, she was seen carrying a small bag, which detectives assumed contained the Christmas card for her penpal.

A gold heart-shaped locket necklace like the one Rhianna was believed to be wearing on the day she disappeared.

Her mother arrived home from work at 4:10pm to a normal scene: a locked door, the television blasting afternoon programming, a record sitting on the living room floor as if it had been played and then carelessly discarded.

Most tellingly, the Christmas card Rhianna had been so eager to buy was sitting on the table, meaning that she had returned home at some point in the afternoon.

Only Rhianna was nowhere to be seen.

None of her personal belongings were missing.

If she had left of her own accord, she didn't expect to be gone for long.

Police surmised that it was more likely that she didn't.

A poster advertising Rhianna’s disappearance.

Panicked, Paula Barreau called her daughter's friends, knocked on neighbours door, and by 6pm was panicked enough to file a missing person's report.

"I was hoping she was just at a friend's place and had forgotten what the time was - but that's not like her," Paula Barreau told Adelaide Now in 2015, the first time she had spoken publicly about her daughter's disappearance since the abduction, and the only interview either parent has conducted to date.

More details of Rhianna's movements that day emerged.

Just ten minutes before her mother returned home, Rhianna was spotted near a junction roughly 500 metres from her house.

She was alone, but - according to her official Missing Persons report - "Suspicious activities occurred at Acre Avenue, David Terrace, Highwray Avenue, and Crittenden Avenue Morphett Vale."

Police said this man tried to entice a 13-year-old girl into a white, early model Holden Torana sedan about the same time Rhianna disappeared.